We lived on the top floor of a 5th floor walk-up brownstone. The building was old and I always had the feeling that the staircase would just give spontaneously one day. Ha ha.
We too had cranky neighbors and I remember reading that other mamas have left bottles of wine outside the door of neighbors with notes that say "The baby is coming soon. Hope this wine will drown out any strange sounds that come from our apartment." Then I remembered how awful my neighbors were and planned to just leave a note on our door saying "Yes, we are having a planned homebirth. No need to call 911." But in the end, we didn't do any of these things. And I was not a quiet mama. Not one person said a thing to us after. So like others have said, "who cares what your neighbors think" and they probably won't even know.
Good luck to you!